This invention relates to the field of occluding devices and the methods of using such devices, and more particularly to contraceptive and sterilization devices.
Conventional contraceptive strategies generally fall within three categories: physical barriers, drugs and surgery. While each have certain advantages, they also suffer from various drawbacks. Barriers such as condoms and diaphragms are subject to failure due to breakage and displacement. Drug strategies, such as the pill and Norplant(trademark), which rely on artificially controlling hormone levels, suffer from known and unknown side-effects from prolonged use. Finally, surgical procedures, such as tubal ligation and vasectomy, involve the costs and attendant risks of surgery, and are frequently not reversible. Thus, there remains a need for a safe, effective method of contraception, particularly a non-surgical method which is reversible.
This invention is directed to a device for occluding a body lumen, generally comprising a tubular member, and a mesh member transversely disposed on the tubular member which is permeable to allow for tissue ingrowth. The tissue ingrowth produces a tissue impregnated mesh which occludes the body lumen. A presently preferred embodiment is a contraceptive or sterilization device for occluding a reproductive tract or lumen to prevent the passage of reproductive cells through the tract or lumen. For example, the occluding device of the invention can be used in the fallopian tubes of a female patient, or the vas deferens of a male patient. However, the occluding device of the invention can be used in other body lumens or passageways. For example, the occluding device of the invention can be used to repair a cardiac malformation, known as a ventricular septal defect, in which a passageway is formed in the heart wall that separates the right and left ventricles of the heart allowing blood leakage between the two ventricles. Thus, the occluding device of the invention is secured to the heart wall defining the septal defect, and ingrowth of the myocardium into the device mesh member occludes the passageway to thereby repair the defect. Similarly, atrial septal defects or other passageways in the heart and elsewhere in the body may be occluded using the device of the invention.
In accordance with the invention, the tubular member has a first end, a second end, and a lumen extending therein. The mesh member extends transversely on the tubular member, so that cellular invasion through the mesh member occludes the tubular member lumen and, consequently, the body lumen in which it is installed. In a presently preferred embodiment, the mesh member is disposed within the lumen of the tubular member. However, the transversely disposed mesh member may be outside of the tubular member lumen, as for example, where the mesh member comprises an end cap having a peripheral edge connected to an end of the tubular member. The tissue impregnated mesh forms an occluding member with improved durability over synthetic occluders, which are more vulnerable to rupture or failure within the body due to their synthetic structures. Moreover, the occluding device is highly flexible which facilitates the introduction and retention of the device within the body lumen.
In a presently preferred embodiment, the mesh member comprises strands of a material woven or bundled into a permeable structure. However, other suitable permeable structures may be used, including a porous membranal structure which allows for tissue ingrowth. The mesh member is formed from a biocompatible material, such as a metal, polymeric material, and organics such as animal tissues, and is preferably reactive to tissue so as to promote the tissue ingrowth into the mesh member.
Preferably, the tubular member is at least in part expandable within the body lumen from a first configuration suitable for introduction into the body lumen to a second larger configuration to facilitate securing the expanded tubular member to at least a portion of a wall which defines the body lumen. In one presently preferred embodiment, the tubular member has an open or lattice-like framework which allows for the growth of tissue through the openings of the lattice-like framework, so as to interconnect the tubular member and the wall of the body lumen. The surface of the tubular member may be treated to promote the tissue ingrowth.
The occluding device of the invention may be advanced to the desired location within the body lumen by a suitable delivery system, such as a delivery catheter or a conventional balloon catheter similar to those used for delivering stents, aortic grafts and various types of prosthesis. The device is introduced and positioned within the region of the body lumen to be occluded with the tubular member in the first configuration with small transverse dimensions. Once in place, the tubular member is then expanded to the second configuration with transverse dimensions roughly corresponding to or slightly larger than the body lumen, so that the tubular member can be secured to the wall defining the body lumen. The tubular member may be self expanding or expanded by mechanical devices or by inflation of the balloon of the balloon catheter. The tubular member will then remain in the open configuration implanted in the body lumen.
With the open, lattice-like framework of the tubular member expanded within the body lumen, tissue ingrowth, or epithelialization, through the open framework of the tubular member secures it to the wall defining the body lumen. At the same time, epithelialization through the mesh member occludes the body lumen. Sufficient epithelialization to secure the device to the body wall and occlude the body lumen may take one or more weeks. While the term xe2x80x9cepithelializationxe2x80x9d is used herein, it should be understood that, depending on the body lumen, tissues such as endothelium or myocardium may be impregnating the device. Additionally, scar tissue formation may take place as well.
One presently preferred embodiment of the invention comprises a reversible contraceptive system which reversibly occludes the reproductive body lumen. The tissue impregnated mesh may be reopened by any number of suitable means. For example, the occluding member may be partially or completely cut away using an atherectomy type catheter or laser to create a lumen, and then compressed using a balloon dilatation catheter similar to an angioplasty procedure. Alternatively, a plug may be releasably secured to the mesh member, so that the plug may be detached from the tissue impregnated mesh member to reopen the lumen. Thus, the contraceptive device of the invention can be left in place to effectively block the passageway until the patient wishes to reverse the procedure.
The contraceptive or sterilization device of the invention provides effective sterilization or contraception for both males and females due to the tissue impregnated mesh member which occludes the reproductive body lumen and which has excellent durability. The device remains in place within the reproductive body lumen, and the tissue impregnated mesh member resists degradation or tearing, to thereby decrease the risk of failure of the device. Moreover, the implantation of the device can be performed in a single office visit, using minimally invasive and easily used devices such as hysteroscopes, catheters, guidewires, guiding catheters and the like. These and other advantages of the invention will become more apparent from the following detailed description of the invention when taken in conjunction with the accompanying exemplary drawings.